ICP DAS GW-7838-M Modbus TCP Server to M-Bus Master Gateway User Manual

: June 13, 2024
: ICP DAS

Table of Contents

GW-7838-M Modbus TCP Server to M-Bus Master Gateway
Product Information
Product Usage Instructions
1. Getting Started
2. Configuration and Communicate Test
3. Firmware Update

GW-7838-M Modbus TCP Server to M-Bus Master Gateway

Product Information

Product Name: GW-7838-M (Modbus TCP Server to
M-Bus Master Gateway)

User Manual Version: 1.0.1 Oct 2021

Model Number: GW-7838-M

Description: The GW-7838-M is a Modbus TCP
Server to M-Bus Master Gateway. It supports the M-Bus standard
(EN-13757, CJ/T -188) and Modbus TCP/RTU function code 0x03 and
0x04 to read meter data. The baud rate is adjustable by dip switch
for M-Bus and serial port, ranging from 300 to [unspecified
value].

Product Usage Instructions

1. Getting Started

To get started with the GW-7838-M, follow the steps below:

Ensure that you have read and understood the user manual.
Connect the GW-7838-M to the power supply and network using the
appropriate cables.
Refer to the LED indicator section (2.1) to understand the
status indications.
Refer to the DIP switch section (2.2) to configure the desired
settings.

2. Configuration and Communicate Test

To configure and perform a communicate test with the GW-7838-M,
follow the steps below:

Connect the GW-7838-M to the M-Bus meter(s) using the
appropriate cables.
Adjust the baud rate and data format settings as described in
section 3.2.
Configure the M-Bus meter settings according to section
3.3.
Perform the M-Bus meter communicate test as outlined in section
3.4.

Note: It is important to refer to the user manual for detailed
instructions and specific settings related to configuration and
communication tests.

3. Firmware Update

If a firmware update is required for the GW-7838-M, please refer
to Appendix A of the user manual for detailed instructions on how
to perform the update.

For any further assistance or troubleshooting, please contact us
via email at service@icpdas.com. We will respond to your inquiry as
soon as possible.

User Manual
Version 1.0.1 Oct 2021
GW-7838-M
(Modbus TCP Server to M-Bus Master Gateway)

Table of Contents

1. Introduction …………………………………………………………………………………………………………. 4 1.1 Features………………………………………………………………………………………………………….. 5 1.2 Specification…………………………………………………………………………………………………….. 6

2. Getting Started …………………………………………………………………………………………………….. 7 2.1 LED Indicator …………………………………………………………………………………………………… 8 2.2 DIP Switch ………………………………………………………………………………………………………. 9

3. Configuration and Communicate test ………………………………………………………………….. 10

3.1 Connect…………………………………………………………………………………………………………. 11

3.2 Baud Rate and Data Format Settings ………………………………………………………………… 12

3.3 M-Bus Meter Settings………………………………………………………………………………………. 13

3.3.1 3.3.2 3.3.3 3.3.4 3.3.5 3.3.6

Import ……………………………………………………………………………………………………… 14 Export ……………………………………………………………………………………………………… 16 Add …………………………………………………………………………………………………………. 17 Save ……………………………………………………………………………………………………….. 19 Delete ……………………………………………………………………………………………………… 21 Delete All …………………………………………………………………………………………………. 23

3.4 M-Bus Meter Communicate Test ……………………………………………………………………….. 24

4. Meter Configuration Label Description ………………………………………………………………… 25 4.1 Serial…………………………………………………………………………………………………………….. 26 4.2 Protocol…………………………………………………………………………………………………………. 27 4.3 SubCode ……………………………………………………………………………………………………….. 28 4.4 Medium …………………………………………………………………………………………………………. 29 4.5 Value …………………………………………………………………………………………………………….. 30 4.6 Unit ………………………………………………………………………………………………………………. 31 4.7 Cycle …………………………………………………………………………………………………………….. 32 4.8 Description …………………………………………………………………………………………………….. 33 4.9 Register…………………………………………………………………………………………………………. 34

Appendix A. Firmware Update …………………………………………………………………………………… 35

Appendix B. Revision History ……………………………………………………………………………………. 36

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Important Information
Warranty
All products manufactured by ICP DAS are under warranty regarding defective materials for a period of one year, beginning from the date of delivery to the original purchaser.
Warning
ICP DAS assumes no liability for any damage resulting from the use of this product.ICP DAS reserves the right to change this manual at any time without notice. The information furnished by ICP DAS is believed to be accurate and reliable. However, no responsibility is assumed by ICP DAS for its use, not for any infringements of patents or other rights of third parties resulting from its use.
Copyright
Copyright @ 2020 by ICP DAS Co., Ltd. All rights are reserved.
Trademark
Names are used for identification purpose only and may be registered trademarks of their respective companies.
Contact us
If you encounter any problems while operating this device, feel free to contact us via mail at: service@icpdas.com . We will reply as soon as possible.

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1. Introduction

The M-Bus (“Meter-Bus”) is a standard for remote reading of meters. It is usable for most types of consumption meters as well as for various sensors and actuators. The GW-7838-M is specially designed for M-Bus slave device. It offers Modbus TCP communication by Ethernet and Modbus RTU communication by RS-232. On hardware the GW-7838-M has a 6-bit dip switch for serial port and M-Bus port baud rate. GW-7838-M supports Modbus TCP/RTU function code 0x03 and 0x04 to read data of M-Bus meters. Through this design, it is easy to communicate with any standard M-Bus slave.

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1.1 Features
Supports M-Bus standard: EN-13757, CJ/T -188 Supports Modbus TCP/RTU function code 0x03 and 0x04 to read Meter data Baud rate: Adjustable by dip switch for M-Bus and serial port from 300 to
115200 bps. Default M-Bus port data format: Data bit 8, Parity Even, Stop bit 1 Supports up to 100 M-Bus slaves M-Bus over current protection Short-circuit protection on the M-Bus Update firmware from serial port Provides PWR, MTX and MRX 3 LED indicators Watchdog inside

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1.2 Specification

Module
M-Bus Interface Channel Baud Rate (bps) Data bit Stop bit Parity Isolation ESD Protection Current Protection UART Interface Channel Baud Rate (bps) ESD Protection Ethernet Interface Channel Protocol Power Power Supply Protection
Power Consumption
Mechanical Installation Dimension (W x L x H) Environment Operating Temperature Storage Temperature Relative Humidity

GW-7838-M
1 300 bps ~ 2400 bps 5, 6, 7, 8 1, 2 None, Even, Odd, Space, Mark 3750 Vrms for photo-couple Contact ±4 kv class B short-circuit protection
1 RS-232 300 bps ~ 115200 bps Contact ±4 kv class B
1 Modbus TCP
Unregulated +10 ~ +30 VDC Power reverse polarity protection, Over-voltage brown-out protection 1.8 W @ 24 VDC (with 1 slave device) 11.8 W @ 24 VDC (with 100 slave devices)
DIN-Rail 72mm x 122mm x 33mm
-25 to +60°C -40 to +80°C 10 to 90% RH, Non-condensing

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2. Getting Started
Appearance and pin assignments

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2.1 LED Indicator
The GW-7838-M module provides three LED indicators, including indicators for power status and module status. The Following is an overview of the purpose and function of each LED indicator together with a description.

LED Name Power (Yellow) Power (Yellow)
MTX (Green) MRX (Green) *

LED Status
ON
Flashing
Flashing Flashing

LED Description
The power of the module is ON M-Bus overload (short or too much M-Bus slaves) Need reboot to recover the status. M-Bus communication normal Tx
M-Bus communication normal Rx

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2.2 DIP Switch

The GW-7838-M module provides 6-bit dip switches and the first two bits are used to change

operation mode. The following is an overview of the purpose and function of each dip switch

position together with a description. After changing the configuration of the DIP switch, the

GW-7838-M needs to reboot to enable the new setting.

1 (Init)
OFF

2 (Mode) Description

OFF

Normal Work

ON

OFF

Firmware Update

OFF

ON

Configuration mode

ON

Reserve

The DIP switch 3 ~ 6 are used to set RS-232 and M-Bus baud rate. The following is an overview

of the purpose and function of each dip switch position together with a description. After

changing the configuration of the DIP switch, the GW-7838-M needs to reboot to enable the new setting.

3 4 5 6 M-Bus baud rate (bps)

OFF OFF OFF OFF 300

ON OFF OFF OFF 600

OFF ON OFF OFF 1200

ON ON OFF OFF 2400

OFF OFF ON OFF 4800

ON OFF ON OFF 9600

OFF ON ON OFF 19200

ON ON ON OFF 38400

OFF OFF OFF ON 57600

ON OFF OFF ON 115200

Others

User-defined

Note: M-Bus only supports baud rate from 300 to 2400 bps.

Default M-Bus data format is 8, e, 1.

Default RS-232 data format is 8, n, 1.

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3. Configuration and Communicate test
The configuration for the module parameters or communication setting on the GW-7838-M module can be performed via M-Bus utility. The M-Bus utility can be downloaded from the following website: https://www.icpdas.com/en/download/index.php?model=GW-7838-M
The figure below is an illustration of module wiring. Connect the PC COM port to the RS-232 port and connect M-Bus meter to M-Bus port of the GW-7838-M. Set the DIP switch to the configuration mode and then power it on.

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3.1 Connect
Execute the M-Bus utility. There will be a connection diagram as first.
Click “Configure” tab page, choose the corresponding COM port in PC, or select Ethernet and input GW-7838-M IP Address then click “Connect” button to connect with module. Please be noted that the UART baud rate of GW-7838-M will be 115200bps when it is in configuration Mode.

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3.2 Baud Rate and Data Format Settings
The first page of the utility lists baud rate and data format configuration of the serial port and the M-Bus port and it also shows the Modbus node ID and IP related parameters of the GW-7838-M. User could add a new baud rate and data format setting or change IP address as need in this page. In addition, because of the slow response of some M-Bus meters, the utility also provides an M-Bus timeout setting “M-Bus Timeout”, which users can adjust according to their needs.

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3.3 M-Bus Meter Settings
In the “Meter” page of the utility, user could configure the M-Bus communication setting by using “Import” or “Add” functions. The usages of these functions are listed as following sections.

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3.3.1 Import
There are two ways to add M-Bus Meter setting into GW-7838-M. One is using “Import” to import an existed configuration file and save to GW-7838-M. The configure steps are as following: Step1: Press “Import” button.
Step2: Open an existed configuration file of XML format.

Step3: The configuration will be loaded into the utility as following:

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Step4: Press “Save” button and confirm to save configuration.

Step5: After saving success diagram showed, set the DIP switch to operation mode and reboot the module.

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3.3.2 Export
User could export the existed module configuration to a XML file by the “Export” function.

Step1: Press “Export” button. Then select path and input file name to export the configuration.

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3.3.3 Add
The second way to add meter configuration to GW-7838-M is using “Add” function. The “Add” function can add meter of EN-13757 protocol or CJ/T-188 protocol into GW-7838-M. Refer below operation example for detail setting step.
Step1: Press “Add” button and select the protocol of the meter. There are two protocols, EN-13757 and CJ/T188 for select. Input the meter serial number and M-Bus network polling cycle time. Then press “OK” to connect to the meter.
Some meters supported several data group, this calls subcode. If the data of user needs at different subcode, user can input the subcode number at “Application reset subcode” field. There can add several different subcode in one meter. If user needs not the subcode field, please keep it empty. The below example is using subcode 0x01.
Note: The meter serial number of EN-13757 is 8 numbers, and the serial number of CJ/T188 is 14 numbers.

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Step2: The meter information shows as below.

Step3: After add all meters on the utility list, press “Save” to save these parameters to the GW-7838-M.

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3.3.4 Save
After adding meters setting or importing configuration, use “Save” function to save configuration into the GW-7838-M. Step1: Press “Save” button.
Step2: Confirm to save the configuration.

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Step3: After saving success diagram showed, set the DIP switch to operation mode and reboot the module.

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3.3.5 Delete
The “Delete” function will delete one meter setting each time. Take the following setting as an example.

Step1: Press “Delete” button.

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Step2: Select the serial number of meter which wanting to be deleted. Step3: Confirm to delete meter which is selected. Step4: it will show the meter information after deleting as below.

Step5: After delete meter configuration completely, press “Save” to save change to GW-7838-M.

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3.3.6 Delete All
The “Delete All” function can delete all meters setting on the utility list. Step1: Press “Delete All” button.
Step2: Confirm to delete all meters’ configuration.

Step3: Finally press “Save” to save changing configuration.

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3.4 M-Bus Meter Communicate Test
After the meter is configured, the user can re-execute the M-Bus utility and then click “Gateway Reader” to read the meter data and check if the settings are correct.
After executing the “Gateway Reader”, select the Ethernet and timeout related options, and press the “Start Reader” button to import the configuration file exported in Section 3.3.2.

It can test whether the value read matches the setting.

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4. Meter Configuration Label Description
After adding meters’ configuration, the meters’ information will be showed as below.

There are some labels to record the meters’ information for user’s reference. User can find the meaning of the labels in the following section.

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4.1 Serial
The “Serial” column records serial number of meters. Each meter that complies with the EN-13757 specification will have a set of 8-digit serial numbers, while meters that comply with the CJ / T-188 specification will have a set of 14-digit serial numbers. The meter serial number will be displayed in each meter data in the first column of the “Serial” field.

EN-13757

CJ/T-188

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4.2 Protocol
The “Protocol” field is used to indicate which specification of the meter following. GW-7838-M supports two protocols EN-13757 and CJ/T-188.

EN-13757

CJ/T-188

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4.3 SubCode
If the SubCode field is enabled, it will be filled with the array subcode currently used to read the table data.
Note that the new meter can read the data preset by the meter manufacturer without filling in the subcode during the “Add” process. Once the subcode is filled in, the data read will no longer be the manufacturer default data, unless the meter is added again and fill in the original factory default subcode. It means that once the subcode is set, it will be permanently saved. About the default subcode, user should contact the meter manufacturer for it.

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4.4 Medium
The “Medium” field records medium of meters. It will show the medium of meters according to the definition in EN-13757 protocol or CJ/T-188 protocol.

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4.5 Value
The “Value” field records value type of meters’ data. It will show the value type of meters’ data according to the definition in EN-13757 protocol or CJ/T-188 protocol.

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4.6 Unit
The “Unit” field records unit of meters’ data. It will show the unit of meters’ data according to the definition in EN-13757 protocol or CJ/T-188 protocol.

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4.7 Cycle
The “Cycle” field records the minimum cycle time (unit is sec.) for polling all meters’ data. Please be noted that the cycle time parameter is for all meters of the M-Bus network.

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4.8 Description
The ” Description” field records meaning of meters’ data. It will show the real meaning of meters’ data according to the definition in EN-13757 protocol or CJ/T-188 protocol.

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4.9 Register
The “Register” field records the total word count and the Modbus address of every data at GW-7838-M. Take the below as an example, this is a water meter (Medium) of EN-13757 protocol (Protocol) with serial number 10153802 (Serial). It has total 4 words data length (Register) and 1st data is 8 digit BCD type (Value) from Modbus address 0x0000 ~ 0x0001 (Register) and 2nd data is also 8 digit BCD type (Value) from Modbus address 0x0002 ~ 0x0003 (Register). The GW-7838-M will update the meter data as fast as per 60 second one time (Cycle).
Note: If GW-7838-M updates all meters data faster than setting cycle time 60 second, the all meters data will be update every 60 second. But if slower than 60 seconds, GW-7838-M will update all meters data as soon as possible.

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Appendix A. Firmware Update
The firmware on the GW-7838-M module can be updated via COM Port. The latest firmware file (*.fw file) and the latest version of the firmware update utility (FW_Update_Tool.zip) are available from the web link below. A notification will not be sent when a new version is released.
https://www.icpdas.com/en/download/index.php?model=GW-7838-M Following shows the firmware update process for GW-7838-M using firmware update utility. Step 1: Switch DIP switches to the firmware update mode (Init ON) and reboot the module. Step 2: Run firmware update utility, FW_Update_Tool_vX.XX.exe (X denotes version number).

Download the Firmware: (1) Click the “Browser…” button to select the location of the firmware file. The name of the firmware file is GW-7838_XXX.fw (X denotes version number). (2) Click the ” Firmware Update” button to being the firmware update process. Once the firmware has been successfully updated, a notification “Firmware Update Success” will be displayed.

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Appendix B. Revision History

This chapter provides revision history information to this document. The table below shows the revision history.

Revision 1.0.0

Date October 2021

Description First Release

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